KR100579388B1 - Light emitting diode package employing a heat sink with a sprial groove - Google Patents

Abstract

Disclosed is a light emitting diode package employing a heat sink having a spiral groove. The LED package includes a first lead terminal having an annular first connection portion at one end thereof. The second lead terminal is spaced apart from the first lead terminal. The second lead terminal has a second connection portion located near the first connection portion. On the other hand, the heat sink is fastened to the annular first connection portion is located. The heat sink has a spiral groove on an upper side thereof to be fastened to the first connection portion. In addition, a package body supports the first lead terminal, the second lead terminal, and the heat sink. The package body has an opening that exposes the second connection portion and the top surface of the heat sink. Accordingly, the heat sink and the lead terminal may be directly connected to reduce the number of bonding wires, thereby facilitating a light emitting diode package manufacturing process.

Light Emitting Diode, Lead Terminal, Heat Sink, Package Body, Spiral Groove

Description

LIGHT EMITTING DIODE PACKAGE EMPLOYING A HEAT SINK WITH A SPRIAL GROOVE}

1 is a perspective view illustrating a light emitting diode package employing a conventional heat sink.

2 and 3 are a perspective view and a plan view for explaining a light emitting diode package employing the heat sink of the present invention, respectively.

4 is a cross-sectional view of a light emitting diode die and a lens mounted on the light emitting diode package of FIG. 2 to describe a light emitting diode package employing the heat sink of the present invention.

5 and 6 are plan views illustrating lead terminals used in the LED package of the present invention, respectively.

(A brief description of the main symbols in the drawings)

10: light emitting diode package, 11: package body,

13: heatsink, 15, 16: lead terminal,

17: light emitting diode die, 19: bonding wire,

21: lens

The present invention relates to a light emitting diode package employing a heat sink, and more particularly, by directly connecting a lead terminal and a heat sink by adopting a heat sink having a spiral groove, it is easy to connect a bonding wire and disconnect the bonding wire. It relates to a light emitting diode package that can prevent the.

Recently, the use of light emitting diodes (LEDs) as light sources is increasing. In general, in order to be used for a purpose such as a light source for illumination, it is required that the light emitting diode have a luminous power of several tens of lumens or more. The light output of the light emitting diode is generally proportional to the input power. Therefore, a high light output can be obtained by increasing the power input to the light emitting diode. However, increasing the input power increases the junction temperature of the light emitting diode. The increase in junction temperature of the light emitting diode leads to a decrease in photometric efficiency, which indicates the degree to which the input energy is converted into visible light. Therefore, it is required to prevent an increase in the junction temperature of the light emitting diode according to the increase of the input power. To this end, a light emitting diode package has been introduced that attaches a light emitting diode to a heat sink and emits heat generated by the light emitting diode through the heat sink.

A light emitting diode package (hereinafter, referred to as an LED package) employing the heat sink is described by Carey et al. In US Pat. No. 6,274,924 (B1) entitled “surface mountable led package”. It has been disclosed.

1 is a perspective view for explaining the LED package 100 disclosed in the US Patent No. 6,274,924 (B1).

Referring to FIG. 1, a heat sink 103 is disposed inside an insert-molded body 101. The body 101 is a plastic material molded around a metal frame. The heat sink 103 may include a reflective cup 113. Meanwhile, a light emitting diode die (LED die) 105 is mounted to the heat sink 103 via a submount 109 that is directly or indirectly thermally conductive. Meanwhile, bonding wires (not shown) extend from the LED die 105 and the submount 109 to the metal lead terminals 111. The lead terminals 111 are electrically and thermally isolated from the heat sink 103. In addition, an optical lens 107 may be added.

As a result, since the LED die 105 is thermally coupled onto the heat sink 103, the LED die 105 can be maintained at a low junction temperature. Therefore, a relatively large input power can be supplied to the LED die 105, thereby obtaining a high light output.

However, since the heat sink 103 is electrically insulated from the lead terminals 111, at least two bonding wires for electrically connecting the LED die 105 and the lead terminals 111 are required. . Increasing the number of bonding wires that are connected makes the bonding wire connection process difficult, and increases the problems such as disconnection and / or short circuits while using the LED package.

On the other hand, when the heat sink is inserted into the main body, the heat sink may be separated from the main body. Therefore, there is a need for a light emitting diode package capable of preventing the heat sink from being separated from the main body.

In addition, the LED package generally includes a lens that emits light emitted from the LED die within a certain direction angle. The lens may be a pre-molded lens or a lens formed by molding an epoxy. However, such lenses are easy to separate from the light emitting diode package. Therefore, there is a need for a light emitting diode package capable of preventing the lens from being separated from the light emitting diode package.

An object of the present invention is to provide a high output light emitting diode package that can reduce problems such as disconnection and / or short circuit of the bonding wire.

An object of the present invention is to provide a light emitting diode package in which a heat sink and a lead terminal can be directly connected.

Another object of the present invention is to provide a light emitting diode package capable of preventing the heat sink or the lens from being separated from the main body.

In order to achieve the above technical problem, the present invention provides a light emitting diode package employing a heat sink having a spiral groove. A light emitting diode package according to an embodiment of the present invention includes a first lead terminal having an annular first connection portion at one end thereof. The second lead terminal is spaced apart from the first lead terminal. The second lead terminal has a second connection portion located close to the first connection portion. On the other hand, the heat sink is fastened to the annular first connection portion is located. The heat sink has a spiral groove on an upper side thereof to be fastened to the first connection portion. In addition, a package body supports the first lead terminal, the second lead terminal, and the heat sink. The package body has an opening that exposes the second connection portion and the top surface of the heat sink. Accordingly, the heat sink and the lead terminal may be directly connected to reduce the number of bonding wires. In addition, it is easy to fasten the heat sink to the first connection portion, which facilitates a light emitting diode package manufacturing process.

The heat sink may have a base and a protrusion protruding upward from a central portion of the base. In this case, the spiral groove is located on the side of the protrusion. Therefore, it is possible to promote heat dissipation while reducing the size of the LED package.

Meanwhile, the first connection part of the first lead terminal may have a ring shape with a portion removed. As a result, the second connecting portion of the second lead terminal can be located closer to the heat sink.

The package body may be formed by fastening the heat sink to the first connection part of the first lead terminal, positioning the second lead terminal, and inserting and molding a thermoplastic resin. Accordingly, a package body having a complicated structure can be easily formed.

The heat sink may have a locking groove on the side of the base portion. The locking groove may be formed in an uneven shape. The locking groove accommodates a portion of the package body to prevent the heat sink from being separated from the package body.

The light emitting diode package may further include a light emitting diode die mounted on the protrusion. A bonding wire electrically connects the LED die and the second connection portion.

In addition, the package body may further have a lens receiving groove located along the outer periphery. The encapsulant may fill the opening of the package body and the lens receiving groove and cover the upper portion of the LED die. Thus, the bonding force between the encapsulant and the package main body is increased, thereby preventing the encapsulant from being separated from the light emitting diode package. The encapsulant may be a lens, and may have a shape of a convex lens such that the light emitted from the LED die is emitted within a predetermined direction angle.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention; The following embodiments are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

2 and 3 are a perspective view and a plan view for explaining a light emitting diode package 10 employing a heat sink 13 according to an embodiment of the present invention, respectively, Figure 4 is a light emitting according to an embodiment of the present invention 2 is a cross-sectional view of the light emitting diode die 17 and the lens 21 mounted on the light emitting diode package 10 of FIG. 2. 5 is a plan view illustrating lead terminals 15 and 16 used in the LED package 10 according to an embodiment of the present invention, and FIG. 6 is a LED package according to another embodiment of the present invention. It is a top view for demonstrating the lead terminal used for the.

2 to 5, the LED package 10 includes a pair of lead terminals 15 and 16, a heat sink 13, and a package body 11 supporting the lead terminals and the heat sink. .

The first lead terminal 15 has a ring-shaped first connecting portion 15a with a portion thereof removed, and has an outer lead terminal 15b extending from the first connecting portion and protruding to the outside of the package body 11. . As shown in FIG. 6, the first lead terminal may be a lead terminal 25 having a closed ring-shaped connecting portion 25a. In addition, the second lead terminal 16 has a second connecting portion 16a, and has an external lead terminal 16b extending from the second connecting portion 16a and protruding to the outside. The second lead terminal 16 is spaced apart from the first lead terminal 15, and the second connecting portion 16a is positioned close to the first connecting portion 15a of the first lead terminal 15. .

As shown in FIG. 5, when the first connection part 15a is a ring shape with a portion removed, the second lead terminal 16 may be located closer to the center of the first connection part than in FIG. 6. . As the second lead terminal 16 is positioned closer to the center of the first connecting portion 15a, the size of the package main body 11 can be reduced, and the bonding wire 19 can be easily connected. On the other hand, the portion removed from the first connecting portion 15a is preferably 1/4 or less of the entire ring. That is, as the removed portion is smaller, the contact surface of the first connecting portion 15a and the heat sink 13 is increased, thereby strengthening the electrical connection. Therefore, the following description will be made based on the lead terminals 15 and 16 of FIG. However, the present invention is not limited to the lead terminals 15 and 16 of FIG. 5, and the lead terminals 25 and 26 of FIG. 6 may also be used.

The heat sink 13 has a spiral groove 13a on its upper side. The heat sink is fastened to the first connecting portion 15a by using the spiral groove 13a and spaced apart from the second lead terminal 16. Therefore, the heat sink is directly electrically connected to the first lead terminal 15, and the heat sink 13 is prevented from being separated from the light emitting diode package 10.

On the other hand, as shown in Figure 4, the heat sink 13 may have a base and a protrusion protruding upward from the center portion of the base. At this time, the spiral groove (13a) is located on the upper side surface of the protrusion. The protrusion is cylindrical as shown, but the base is not limited to the cylindrical shape, various shapes are possible. On the other hand, the outer shape of the package body 11 may be modified according to the shape of the base of the heat sink 13. For example, when the shape of the base portion is a cylinder, the outer shape of the package body 11 may be a cylinder as shown, when the shape of the base portion is a square pillar, the shape of the package body 11 is a square pillar. Can be.

In addition, the heat sink 13 may have a locking groove on the base side surface 13b. The locking groove may be formed in a portion of the base side surface 13b, but may be continuous along one surface. Since the bottom surface of the heat sink 13 is wider to promote heat dissipation, as shown in FIGS. 2 and 4, the lower end of the side of the base may be exposed to the outside. However, the locking groove and the base side surface thereon are covered with the package body 11. Therefore, the locking groove receives a portion of the package body 11, whereby the heat sink 13 is further prevented from being separated from the package body 11.

The heat sink 13 is formed of a conductive material, and in particular, may be formed of a metal or an alloy such as copper (Cu) or aluminum (Al). In addition, the heat sink 13 may be formed using a molding technique or a press working technique.

The package body 11 supports the heat sink 13 and the lead terminals 15 and 16. The package body 11 is formed by placing the lead terminals 15 and 16, fastening the heat sink 13 to the first connection part 15a, and inserting and molding a thermoplastic resin. Thus, the package body 11 fills the engaging groove of the heat sink 13 and fixes the heat sink 13 and the lead terminals 15 and 16 to each other.

The package body 11 has an opening that exposes an upper portion of the heat sink 13 and a second connection portion 16a of the second lead terminal 16. The opening may expose the first connection part 15a of the first lead terminal 15. In this case, the protrusion of the heat sink 13 may protrude above the top surface of the package body 11, as shown in FIG. 4. In addition, the package body 11 may further have a lens receiving groove 11a positioned along the outer periphery. The lens accommodating groove 11a accommodates the lens 21 to prevent the lens 21 from being separated from the package body 11. In addition, a marker 11b may be formed in the package body as shown in FIGS. 2 and 3 to indicate the positions of the lead terminals 15 and 16. The marker 11b indicates the position of the lead terminal 15 directly connected to the heat sink 13 and the spaced lead terminal 16.

Referring again to FIG. 4, the LED die 17 is mounted on the heat sink 13. The light emitting diode die 17 may be made of a compound semiconductor of (Al, In, Ga) N, and is selected to emit light of a desired wavelength. For example, the light emitting diode die 17 may be a compound semiconductor emitting blue light.

In addition, the LED die 17 may have an upper electrode and a lower electrode on its upper and lower surfaces, respectively. The lower electrode is attached to the heat sink 13 by a conductive adhesive such as silver (Ag) epoxy. Since the heat sink 13 is directly electrically connected to the first lead terminal 15, the LED die 17 is electrically connected to the first lead terminal through the heat sink. Therefore, the bonding wire used in the prior art for connecting the LED die 17 and the first lead terminal 15 may be omitted. The upper electrode of the LED die 17 is connected to the second connecting portion 16a of the second lead terminal 16 through the bonding wire 19.

Alternatively, the LED die 17 may have two electrodes on the same surface. In this case, the two electrodes are electrically connected to the lead terminals 15 and 16 via bonding wires, respectively. In this case, since the first lead terminal 15 is directly and electrically connected to the heat sink 13, the bonding wire may be sufficient to connect the LED die 17 and the heat sink 13. Therefore, the process of connecting the LED die 17 and the heat sink 13 with a bonding wire is easier than in the prior art.

Meanwhile, the encapsulant 21 covers the upper portion of the light emitting diode die 17. The encapsulant 21 may be an epoxy resin or a silicone resin. In addition, the encapsulant may include a phosphor that converts the wavelength of light emitted from the LED die 17. For example, when the LED die 17 emits blue light, the encapsulant 21 may include a phosphor for converting blue light into yellow light or converting blue light into green light and red light. As a result, white light is emitted from the light emitting diode package to the outside.

The encapsulant 21 may fill the opening of the package body 11 and the lens receiving groove 11a. Therefore, the bonding force between the encapsulant 21 and the package main body 11 is increased to prevent the encapsulant from being separated from the light emitting diode package. Meanwhile, the encapsulant 21 may be a lens, and may have a convex lens shape as shown in FIG. 5 so that the light emitted from the LED die 17 is emitted within a predetermined direction angle. Therefore, since the lens formed of the encapsulant 21 is strongly coupled to the package main body 11, the lens may be prevented from being separated from the package main body.

According to embodiments of the present invention, the number of bonding wires can be reduced compared to the prior art to provide a high output light emitting diode package that can reduce problems such as disconnection and / or short circuit of the bonding wires. In addition, by adopting a heat sink having a spiral groove, it is easy to fasten the heat sink to the lead terminal, and the heat sink can be prevented from being separated from the light emitting diode package. In addition, a light emitting diode package capable of preventing the lens from being separated from the main body can be provided.

Claims (5)

A first lead terminal having a ring-shaped first connection at one end; A second lead terminal having a second connecting portion positioned close to the first connecting portion and spaced apart from the first lead terminal; A heat sink coupled to the annular first connection part having a spiral groove on an upper side thereof; And And a package body supporting the first lead terminal, the second lead terminal, and the heat sink, the package body having an opening for exposing the second connection portion and the top surface of the heat sink. The method according to claim 1, The heat sink has a base portion and a protrusion protruding upward from a central portion of the base portion, wherein the spiral groove is located on the side of the protrusion. The method according to claim 1, The light emitting diode package of claim 1, wherein the first connection portion of the first lead terminal has a ring shape with a portion removed. The method according to any one of claims 1 to 3, A light emitting diode die mounted on the heat sink; And And a bonding wire electrically connecting the LED die and the second connection part. The method according to claim 4, The package body further has a lens receiving groove located along the outer periphery, And a convex lens-shaped encapsulant filling the opening and the lens receiving groove and covering the upper portion of the LED die.

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